Absorbent article and method for manufacturing an absorbent article

ABSTRACT

An absorbent article including a liquid-permeable topsheet, a liquid-impermeable backsheet and an absorbent core sandwiched between the topsheet and the backsheet, the article being arranged along a longitudinal axis and a transversal axis extending in a perpendicular direction in relation to the longitudinal axis and the main article defining a front portion, a back portion and a crotch portion, wherein the absorbent core is formed with a sealing arrangement including two channel sealings extending along the longitudinal axis in the crotch portion and defining a first effective channel sealing width and a second effective channel sealing width, respectively. The sealing arrangement includes two side seams extending along two side edges of the core, the side seams defining a third and fourth effective width, respectively, along the crotch portion and defining a fifth and sixth effective width, respectively, along the front portion and back portion.

TECHNICAL FIELD

The disclosure relates to an absorbent article comprising an absorbentcore sandwiched between a liquid-permeable topsheet and aliquid-impermeable backsheet. The disclosure also relates to anabsorbent core for an absorbent article, and a method for manufacturingan absorbent article of the above-mentioned type.

BACKGROUND

Wearable and disposable absorbent articles, for example in the form ofdiapers, incontinence garments, feminine garments and the like, are wellknown. Such articles are used to absorb, distribute and store varioustypes of body exudates while providing a high level of comfort and senseof dryness to the wearer during use.

A conventional disposable absorbent article in the form of a diaper isnormally designed with a liquid-permeable topsheet, a liquid-impermeablebacksheet and an absorbent core which is sandwiched between the topsheetand the backsheet. The article is arranged along a longitudinal axis andalso along a transversal axis which extends in a perpendicular directionin relation to the longitudinal axis. Furthermore, the article can bedivided into a front portion, a back portion and a crotch portion.

The absorbent article will absorb body exudates when it is worn. Apotential disadvantage which may occur when the absorbent article is inits wet condition is that the crotch portion may sag and hang down. Thistendency for sagging is unwanted and may lead to insufficient comfort,fit and function of the article.

A previously known absorbent article of the above-mentioned kind isdisclosed in the patent document US 2012/316528. This document shows adisposable diaper having an absorbent core which, according to anembodiment, comprises longitudinally extending channels. The purpose ofthe diaper is to provide good liquid handling properties and anincreased flexibility and improved fit during use.

Even though the article disclosed in US 2012/316528 fulfills certainrequirements related to liquid handling and fit, there is a need forfurther improvements. Also, there is a demand for efficient and reliablemanufacturing methods for the above-mentioned type of absorbentarticles.

SUMMARY

The present disclosure is based on the insight that the manufacturing ofan absorbent article, for example a diaper, may be improved by certainfeatures related to a sealing arrangement of the article.

In accordance with the present disclosure, there is provided anabsorbent article, an absorbent core, and a method for manufacturing anabsorbent article.

There is provided an absorbent article comprising a liquid-permeabletopsheet, a liquid-impermeable backsheet and an absorbent coresandwiched between said topsheet and said backsheet, said article beingarranged along a longitudinal axis and a transversal axis extending in aperpendicular direction in relation to the longitudinal axis and saidarticle comprising a front portion, a back portion and a crotch portion,wherein said absorbent core is formed with a sealing arrangementcomprising two channel sealings extending along said longitudinal axisin said crotch portion and defining a first effective channel sealingwidth and a second effective channel sealing width, respectively.Furthermore, the sealing arrangement comprises two side seams extendingalong two side edges of said core, said side seams defining a third andfourth effective width, respectively, along said crotch portion anddefining a fifth and sixth effective width, respectively, along saidfront portion and back portion; said effective widths being defined asthe extension of said sealing arrangement in the transverse direction ofthe article, along any cross-section of the crotch portion, wherein thesum of said first to sixth effective widths in the transversal directionis generally constant along said core.

The disclosure provides certain advantages. The disclosure fulfillsrequirements on absorbent articles related to improved fit, comfort andfunction in its wet condition. Also, due to the above-mentionedarrangement of the effective widths of the sealing arrangement, animproved way of manufacturing the absorbent article can be obtained.

The sealing arrangement may be constituted by a welding pattern which isproduced by means of a thermo- and/or mechanical sealing, such as forexample thermo-sealing or ultrasonic welding.

The sealing arrangement according to claim 1 leads to an improvedmanufacturing of the article in which the sealing can be carried out sothat a generally constant energy transfer along the absorbent core isrequired. The sum of the effective widths of the sealing spots in thetransversal direction of the core is generally constant along anycross-section of said core. A generally constant energy transfer isrequired as the welding of the channel sealings and the side sealingsare produced along the longitudinal direction of the core.

Each “effective width” of a sealing spot is defined as the length of awelding spot in its transverse direction of the article.

The welding pattern may comprise a plurality of welding spots. Thewelding spots may be generally circular, rectangular, oval, or oblong.

The welding pattern may comprise a plurality of welding spots beingarranged in the form of a first row along the longitudinal axis whereineach welding spot extends along a first axis, being different from thelongitudinal axis. Furthermore, a plurality of welding spots beingarranged in the form of a second row along the longitudinal axis whereineach welding spot in the second row extends along a second axis, alsobeing different from the longitudinal axis, and said first axis andsecond axis defining a first angle (α1) in relation to each other. Eachwelding spot according to this aspect has a length and a width whereinthe length is greater than the width. The length may be at least 1.1 or1.2 of the width. The welding spots may be generally rectangular, oval,or oblong.

Said first angle may be 45-130°, 45-100° or 45-70°. The first axis maydefine a second angle with reference to said longitudinal axis which iswithin the interval 30-60°.

The absorbent core may be formed with a centre segment having a firstwidth as defined in the absorbent component between the channelsealings, and two side segments, each having a second width as definedin the absorbent component outside each channel sealing.

The absorbent component may be formed so that the total amount ofabsorbent material in the centre segment is generally equal to, orgreater than, the total amount of absorbent material in each of the sidesegments. When defining that the total amount of absorbent material inthe centre segment is generally equal to, or greater than, the totalamount of absorbent material in each of the side segments is meant thatthe total weight of the absorbent material in the centre segment isgenerally equal to, or greater than, the total weight of absorbentmaterial in each of the side segments.

A third width, b1, may be defined between the channel sealings and afourth width, b2, may be defined between a channel sealing and a sideseam, and the ratio of the first width, a1, and the third width, b1, maybe greater than the ratio of the second width, a2, and the fourth width,b2.

The absorbent component, at least in the crotch portion, may beconfigured so that 33-41 weight % of the total amount of absorbentmaterial is in the centre segment and 25-33 weight % of the totalabsorbent material is in each one of the side segments.

The absorbent material in the absorbent component, at least in thecrotch portion, may comprise pulp material and superabsorbent material,said pulp material having a basis weight which is in the interval of50-400 g/m² and said superabsorbent material having a basis weight whichis in the interval of 100-900 g/m².

The absorbent component, at least in said crotch portion, may beconstituted by 50-100 weight % superabsorbent material and 0-50 weight %pulp material, or 70-100 weight % superabsorbent material and 0-30weight % superabsorbent material.

The ratio of the first width and the third width may be in the interval0.75-0.91, such as 0.80-0.86 and the ratio of the second width and thefourth width may be in the interval 0.57-0.71, such as 0.62-0.66.

The first, second, third and fourth widths may be configured so thatb1<b2*2 and a1<a2*2.

Each one of said channel sealings may have a length which is 5-50%,10-50% or 28-38%, of the total length of said article.

Each channel sealing may have a length which is 10-60%, 20-60% or30-50%, of the length of the absorbent core.

The position of the channel sealings along the longitudinal direction ofthe article may be arranged so that the distance between the front edgeof the article and the front edge of each channel is 15-40%, such as22-25%, of the total length of the article.

The absorbent component may be constituted by one single absorbentcomponent layer being wrapped in said core cover.

The core cover may be formed by a separate upper core cover layer and aseparate lower core cover layer. However, the disclosure is not limitedto a core cover comprising two separate core cover layers. The corecover may also be of one single material layer. The absorbent componentmay be enclosed by one core cover layer folded in two, or enclosed by acontinuous core cover sheet, thereby providing upper and lower corecover sides for wrapping the absorbent component. The core cover may bemade of thermoplastic polymer material. The basis weight of the corecover material may be in the interval 5-20 g/m².

The core cover material may be nonwoven material. The nonwoven layer maybe formed by a variety of different processes, such as spunbonding,airlaying, meltblowing or bonded carded web formation processes. Thenonwoven layer may be made of an SMS (spunbond/meltblown/spunbond) or SS(spunbond/spunbond) nonwoven material of polypropylene or bicomponentfibers of polypropylene and polyethylene, or of a combination of suchmaterials.

The absorbent component may be configured with an ability to expand onwetting and displaying a first volume in dry condition and a secondvolume in completely expanded wet condition, the second volume beinggreater than the first volume. The core cover which is arranged aroundthe absorbent component may constitute volume-limiting means and maydefine and limit an expansion space for the centre segment so that thecenter segment may be prevented from reaching complete expansion to thesecond volume on wetting.

The centre segment of the absorbent component may be configured for astiffness in a wet condition which may be greater than that of each sidesegment, and thus may form a forming element in the absorbent article.

The topsheet may comprise at least one additive material in the form ofa skin care composition, at least above the side segments.

The absorbent core may be generally rectangular.

The channel sealings may be generally parallel to said longitudinal axisand/or the channel sealings may be generally straight.

The channel sealings may be positioned within two corresponding channelswhich constitute sections of the absorbent core which are generally freefrom absorbent material.

There is also provided an absorbent core for an absorbent article, saidabsorbent core comprising a sealing arrangement with two channelsealings extending along said 25 longitudinal axis in said crotchportion and defining a first effective channel sealing width and asecond effective channel sealing width, respectively. Furthermore, thesealing arrangement comprises two side seams extending along two sideedges of said core, said side seams defining a third and fourtheffective width, respectively, along said crotch portion and defining afifth and sixth effective width, respectively, along said front portionand back portion; said effective widths being defined as the extensionof said sealing arrangement in the transverse direction of the article,along any cross-section of the crotch portion, wherein the sum of saidfirst to sixth effective widths in the transversal direction isgenerally constant along said core.

There is also provided a method for manufacturing an absorbent articlecomprising a longitudinal axis and a transversal axis extending in aperpendicular direction in relation to the longitudinal axis and saidarticle comprising a front portion, a back portion and a crotch portion,comprising: forming an absorbent core with an absorbent component andenclosing said absorbent component by a core cover comprising an upperside and a lower side; providing a sealing arrangement with two channelsealings extending along said longitudinal axis in the crotch portionjoining said upper and lower core cover sides and defining a firsteffective channel sealing width and a second effective channel sealingwidth and sandwiching said absorbent core between a liquid-permeabletopsheet and a liquid-impermeable backsheet; and forming said sealingarrangement with two side seams extending along two side edges of saidcore, said side seams defining a third and fourth effective width,respectively, along said crotch portion and defining a fifth and sixtheffective width, respectively, along said front portion and backportion; said effective widths being defined as the extension of saidsealing arrangement in the transverse direction of the article along anycross-section of the crotch portion; and forming said sealingarrangement in a manner so that the sum of said first to sixth effectivewidths in the transversal direction is generally constant along saidcore.

Further advantages and advantageous features of the disclosure aredisclosed in the following description.

BRIEF DESCRIPTION OF THE DRAWINGS

The disclosure will be described in greater detail below with referenceto the figures shown in the appended drawings.

FIG. 1 shows a view from above of an absorbent article in the form of adiaper;

FIG. 2 shows a cross-sectional view of the diaper;

FIG. 3 shows a welding pattern which can be implemented in thedisclosure; and

FIG. 4 shows a further view of a welding pattern.

DETAILED DESCRIPTION

Different aspects of the present disclosure will be described more fullyhereinafter with reference to the enclosed drawings. The embodimentsdisclosed herein can, however, be realized in many different forms andshould not be construed as being limited to the aspects set forthherein.

With initial reference to FIG. 1, there is shown a view from above of anabsorbent article 1 in the form of a baby diaper. The absorbent article1 is shown in FIG. 1 in an unfolded and flat state. Also, the absorbentarticle 1 is based on an absorbent structure for absorbing body exudatesfrom a wearer to provide a dry and comfortable fit for the wearer.

As shown in FIG. 1, the absorbent article 1 comprises a liquid-permeabletopsheet 3, a liquid-impermeable backsheet 4 an absorbent core 5 whichis sandwiched between the 25 topsheet 3 and the backsheet 4. Thetopsheet 3 is arranged at the surface of the article 1, i.e., at theside which is facing the wearer, whereas the backsheet 4 is arranged atthe underside of the article 1. Furthermore, both the topsheet 3 and thebacksheet 4 extend laterally outside of the absorbent core 5 along theentire perimeter of the article 1.

The absorbent core shown in FIG. 1 has a generally rectangular design.However, the disclosure is not limited to this design but can be formedin generally any geometric form within the scope of the disclosure.

The topsheet 3, backsheet 4 and the absorbent core 5 may consist of anymaterials suitable for their purposes, as will be discussed in furtherdetail below.

As shown in FIG. 1, the absorbent article 1 has a longitudinal extensionalong a longitudinal axis y1 and a transverse extension along atransverse axis x1, which is perpendicular to the longitudinal axis y1.Furthermore, the absorbent article 1 can be defined as being dividedinto a front portion 6, a back portion 7 and a crotch portion 8. Thefront portion 6 is intended to be oriented in a direction towards thewearer's belly during use of the article 1.

Furthermore, with reference to FIGS. 1 and 2, wherein FIG. 2 is across-sectional view of the absorbent article 1 along the transversalaxis x1, it should be noted that the absorbent core 5 comprises anabsorbent component 5 a, 5 b, 5 c enclosed by a core cover comprising anupper side 11 and a lower side 12, and is formed with two longitudinallyextending and generally straight channel sealings 9, 10 which areconfigured so as to join the upper core cover side 11 to the lower corecover side 12, see in particular FIG. 2, wherein the absorbent core 5 issandwiched between said upper side 11 and said lower side 12. Accordingto FIGS. 1 and 2, the core cover is formed of a separate upper corecover layer and a separate lower core cover layer. However, thedisclosure is not limited to a core cover comprising two separate corecover layers. The core cover may be of one single material layer. Theabsorbent component may be enclosed by one core cover layer folded intwo, or enclosed by a continuous core cover sheet, thereby providingupper and lower core cover sides for wrapping the absorbent component.

The upper core cover side 11 and the lower core cover side 12 may beattached to each other by thermo-mechanical bonding, such as for examplethermo-sealing or ultrasonic welding. According to the embodiment shownin FIGS. 1 and 2, the upper core cover side 11 and the lower core coverside 12 are attached to each other by ultrasonic welding.

The channel sealings 9, 10 are positioned along two correspondingchannels 13, 14 which constitute sections of the absorbent core 5 whichare not filled with absorbent material. This is obtained throughmanufacturing the absorbent core 5 involving a mat forming processduring which absorbent material is omitted from the areas whichcorrespond to the channels 13, 14. In this manner, no absorbent materialwill be present in the channels 13, 14, i.e., where the channel sealings9, 10 are arranged.

As shown in FIGS. 1 and 2, the absorbent core 5 may be divided into acentre segment 5 a and two side segments 5 b, 5 c in the crotch portion8. The two above-mentioned channels 13, 14, and the channel sealings 9,10 will consequently be configured so that they separate the threesegments 5 a, 5 b, 5 c from each other along the crotch area 8. Also,the length l1 of each channel sealing 9, 10 may correspond to the lengthof the crotch portion 8 and may also be slightly less than the length ofeach channel 13, 14.

The absorbent core 5 may be generally rectangular and comprise twogenerally straight channel sealings 9, 10 which are generally parallelto said longitudinal axis y1 and define a first channel sealing width w1and a second channel sealing width w2. The disclosure is not limited toa rectangular core 5 and generally straight channel sealings 9, 10,i.e., other geometrical configurations may occur. The channel sealings9, 10 are positioned within the first channel 13 and the second channel14, respectively, and are configured to attach the upper core cover side11 to the lower core cover side 12.

Furthermore, the centre segment 5 a is defined in the core 5 between thechannel sealings 9, 10. Also, the two side segments 5 b, 5 c are definedin the core 5 outside each channel sealing 9, 10. More precisely, thefirst side segment 5 b is positioned between the first channel sealing 9and a first side seam 15, whereas the second side segment 5 c ispositioned between the second channel sealing 10 and a second side seam16. The side seams 15, 16 are configured for joining the upper corecover side 11 to the lower core cover side 12, suitably by means ofultrasonic welding or other relevant technologies as described abovewith reference to the channel sealings 9, 10. Furthermore, the sideseams 15, 16 extend along each side of the absorbent core 5, along afirst side edge 17 and a second side edge 18 of the absorbent core 5.

As mentioned, the length l1 of the crotch portion 8 may equal the lengthof the channel sealings 9, 10, i.e., the channel sealings 9, 10 mayextend along the crotch portion 8 only. However, the side seams 15, 16may not just be positioned along the crotch portion 8 but also extendalong the front portion 6 and the back portion 7. This will be describedin detail below.

In summary, the absorbent core 5 is formed with a sealing arrangement9,10,15,16 which may be constituted by the two channel sealings 9, 10and the two side seams 15, 16. The sealing arrangement may be configuredso that, in the crotch portion 8, the absorbent core 5 is divided into acentre segment 5 a and two side segments 5 b, 5 c. More precisely, andas shown in FIG. 2, the centre segment 5 a has a first width a1 and eachside segment 5 b, 5 c has a second width a2. Also, a third width b1 isdefined between the two channel sealings 9, 10. Furthermore, a fourthwidth b2 is defined between the first channel sealing 9 and the firstside seam 15, and also between the second channel sealing 10 and thesecond side seam 16.

According to FIGS. 1 and 2, the absorbent component 5 a, 5 b 5 c may beconfigured so that the total amount of absorbent material of the centresegment 5 a is generally equal to or greater than the total amount ofabsorbent material in each one of the side segments 5 b, 5 c, based onthe weight of the absorbent material. As will be described in greaterdetail below, the absorbent material may comprise a mixture of pulpmaterial and superabsorbent material. Also, the ratio of the first widtha1 and the third width b1 may be greater than the ratio of the secondwidth a2 and the fourth width b2. In practical terms, this means thatthe available space for the absorbent material in the centre segment 5a, in particular during use of the absorbent article 1 in its wetcondition, may be less than the corresponding available space for eachside segment 5 b, 5 c. The absorbent component 5 a, 5 b, 5 c in FIGS. 1and 2 is configured with an ability to expand on wetting and displayinga first volume in dry condition and a second volume in completelyexpanded wet condition, the second volume being greater than the firstvolume. The core cover 11,12 which is arranged around the absorbentcomponent 5 a,5 b,5 c may constitute volume-limiting means and maydefine and limit an expansion space for the centre segment 5 a so thatthe center segment 5 a may be prevented from reaching complete expansionto the second volume on wetting. This will lead to a situation in whichthe centre segment 5 a will be stiffer (in its wet condition) than theside segments 5 b, 5 c. The centre segment 5 a of the absorbentcomponent 5 a,5 b,5 c may be configured for a stiffness in a wetcondition which is greater than that of each side segment 5 b,5 c, andthus may form a forming element in the absorbent article. This meansthat the tendency in the crotch portion 8 of the absorbent article 1 tosag will be reduced, in particular in its wet condition.

The expression “generally equal” as used above for describing the amountof absorbent material in the centre segment 5 a as compared with theside segments 5 b, 5 c should be interpreted in a manner wherein theamount of absorbent material could have a variation of approximately ±5%in any part of the crotch portion 8.

The absorbent component 5 a,5 b,5 c, at least in the crotch portion, maybe configured so that 33-41 weight % of the total absorbent material isin the centre segment 5 a, whereas 25-33 weight % of the total absorbentmaterial is in each one of the side segments 5 b, 5 c. In this manner,the desired stiffness in the centre segment 5 a may be obtained.

In summary, the absorbent core 5 comprises an absorbent component whichin turn comprises the three above-mentioned segments 5 a, 5 b, 5 c inthe crotch portion 8 of the absorbent article 1. In the crotch portion8, the absorbent component 5 a, 5 b, 5 c comprises absorbentmaterial-which may be in the form of pulp material and superabsorbentmaterial. The pulp material may have a basis weight which is in theinterval of 50-400 g/m² and the superabsorbent material may have a basisweight which is in the interval of 100-900 g/m².

Various types of materials may be used for the absorbent article 1. Thetopsheet 3 is arranged to face the wearer of the absorbent article 1when worn. The topsheet 3 may be formed by a fluid permeable nonwovenfabric or film which is made of thermoplastic synthetic fibers. Thetopsheet 3 may be sufficiently liquid-permeable to allow discharged bodyfluids to penetrate through the thickness of the topsheet 3. Also, thetopsheet 3 may be suitably manufactured from a material which iscompliant and soft-feeling to the skin of the wearer. The topsheet 3 mayconsist of a single layer or have a laminate structure comprising aplurality of layers, for example, two or more layers. The layers may bemade of the same material, or some or all the layers may be made ofdifferent materials. The layer of the topsheet 3 or, for the case of alaminate structure, one, some or all the layers of the topsheet may bemade of a single material or have plural portions made of differentmaterials, e.g., within different parts of the wearer-facing surface ofthe topsheet. The layer of the topsheet 3 or, for the case of a laminatestructure, one, some or all the layers of the topsheet may be a nonwovenmaterial, a perforated plastic film, a plastic or textile mesh, or aliquid permeable foam layer. The layer of the topsheet 3 or, for thecase of a laminate structure, one, some or all of the layers of thetopsheet may be, for example, a hydrophilic, non-apertured nonwoven webof fibers, such as natural fibers, e.g., cotton or pulp fibers,synthetic fibers, e.g., polyester or polypropylene fibers, or acombination of these fibers. The topsheet may have a basis weight in therange of 8-40 g/m².

The backsheet 4 may be constituted by a liquid-impermeable andbreathable layer such as a polymeric film, for example a film ofpolyethylene or polypropylene. According to different embodiments, thematerials which may be used for the backsheet 4 include thin andflexible fluid impermeable plastic films, or fluid impermeable nonwovenmaterials, fluid impermeable foams and fluid impermeable laminates. Thebacksheet 4 may be formed by a single layer, but may alternatively beformed by a multi-layered structure, i.e., a laminate, wherein at leastone layer is fluid impermeable. Furthermore, the backsheet 4 may beelastic in any direction. Furthermore, the backsheet 4 may have alaminate structure comprising a liquid barrier sheet and a nonwovenlayer arranged on top of each other (not shown in detail in thedrawings), wherein the nonwoven layer is arranged at an outer side awayfrom the wearer of the absorbent article 1 when worn.

The nonwoven layer may be made of thermoplastic polymer material fibersor filaments. The nonwoven layer may be formed by a variety of differentprocesses, such as spunbonding, airlaying, meltblowing or bonded cardedweb formation processes. The nonwoven layer may be made of an SMS(spunbond/meltblown/spunbond) or SS (spunbond/spunbond) nonwovenmaterial of polypropylene or bicomponent fibers of polypropylene andpolyethylene, or of a combination of such materials. The nonwoven layermay have a basis weight in the range of 5-40 g/m².

The liquid barrier sheet may be made of a plastic material, for examplea thermoplastic film material, and/or a nonwoven material. For example,the liquid barrier sheet may be formed as a plastic layer, e.g., athermoplastic layer, or a plastic film, e.g., a thermoplastic film.Forming the liquid barrier sheet of a plastic material, in particular, athermoplastic film material, allows for a particularly good printabilityof the liquid barrier sheet. The liquid barrier sheet may also containpaper fibers. The liquid barrier sheet may be a liquid impermeable,breathable or non-breathable layer. The liquid barrier sheet may consistof a single layer or have a laminate structure with a plurality oflayers, e.g., two or more layers, three or more layers, or four or morelayers. The layers of the liquid barrier sheet may be laminated, bondedor attached to each other, for example, by thermo and/or mechanicalbonding, such as thermo-sealing, ultrasonic bonding, such as ultrasonicwelding, an adhesive or adhesives, stitching or the like. The liquidbarrier sheet may be a breathable microporous film. The microporous filmmay be made of a material comprising at least two basic components,namely a thermoplastic elastomeric polyolefin polymer and a filler.These components and, in some embodiments, additional other componentscan be mixed together, heated and subsequently extruded into amono-layer or multi-layer film using any one of various film-producingprocesses, such as cast embossed, chill and flat cast, and blown filmprocesses.

The core cover may be formed by a separate upper core cover layer and aseparate lower core cover layer. However, the disclosure is not limitedto a core cover comprising two separate core cover layers. The corecover may also be of one single material layer. The absorbent componentmay be enclosed by one core cover layer folded in two, or enclosed by acontinuous core cover sheet, thereby providing upper and lower corecover sides for wrapping the absorbent component. The core cover may bemade of thermoplastic polymer material. The basis weight of the corecover material may be in the interval 5-20 g/m². The core cover materialmay be nonwoven material. The nonwoven layer may be formed by a varietyof different processes, such as spunbonding, airlaying, meltblowing orbonded carded web formation processes. The nonwoven layer may be made ofan SMS (spunbond/meltblown/spunbond) or SS (spunbond/spunbond) nonwovenmaterial of polypropylene or bicomponent fibers of polypropylene andpolyethylene, or of a combination of such materials. Regarding thechoice of materials for the various layers in the absorbent article, thematerials may be chosen for the bonding process to form the channelsealings and side seams. For example, if ultrasonic welding is chosenfor joining the upper and lower core cover sides, the chosen materialsfor the core cover may be adapted to form a secure bond duringultrasonic welding.

Furthermore, the absorbent core 5 is provided between the topsheet 3 andthe backsheet 4 to absorb the liquid, such as urine or other bodilyfluids, which has passed through the topsheet 3. The absorbent core 5may be made of one or more layers of cellulose fluff pulp andsuperabsorbent material.

The absorbent core 5 may comprise suitable amounts of superabsorbentmaterials. Such superabsorbent material is well known in the field ofabsorbent articles, and is constituted by a water-swellable andwater-insoluble material which is capable of absorbing large quantitiesof fluid upon formation of a hydrogel. The absorbent core 5 may containsuperabsorbent material in the form of fibers or particles of absorbentpolymer material. For example, the superabsorbent material may besurface cross-linked, partially neutralized polyacrylates. Furthermore,the core cover 11, 12 as mentioned above may be made of nonwovenmaterial, with a basis weight of 5-20 g/m².

The superabsorbent material, e.g., the superabsorbent fibers orparticles, may be mixed with other absorbent materials, such ascellulose fluff pulp, and/or arranged in pockets or layers in theabsorbent core 5. The amount of superabsorbent material and pulp in theabsorbent component may be 0-50 weight % pulp fibers and 50-100 weight %superabsorbent material. The absorbent component may further comprisecomponents for improving the properties of the absorbent core 5. Forexample, the absorbent core 5 may comprise a binder or binders, such asbinder fibers.

Furthermore, as known by the skilled person, the various layers of theabsorbent article 1 may be attached by means of adhesive material. Suchadhesive is not shown in the drawings.

One or more additional layers may be provided in the absorbent article1. For example, an acquisition layer may be arranged between theabsorbent core 4 and the topsheet 3. Such an additional layer may forexample be in the form of an airlaid layer, a spunlace layer, ahigh-loft, foam or any other type of material layer which may be used inan absorbent article in order to act as a liquid acquisition andabsorption layer. The acquisition layer is adapted to quickly receiveand temporarily store discharged liquid before it is absorbed by theabsorbent core. Such acquisition layer may be composed of for exampleairlaid nonwoven, spunlace nonwoven, high loft nonwoven or foammaterials. An airlaid nonwoven may be produced with fluff, wood pulp,and here the fluff fibres are dispersed into a fast-moving air streamand condensed onto a moving screen by means of pressure and vacuum.

According to an embodiment, the ratio of the first width a1 of thecentre segment 5 a and the third width b1, i.e., the distance betweenthe channel sealings 9, 10 (i.e., a1/b1) may be in the interval0.75-0.91, such as 0.80-0.86. Furthermore, the ratio of the second widtha2 of each side segment 5 b, 5 c and the fourth width b2, i.e., thedistance between each channel sealing 9, 10 and its corresponding,adjacent side seam 11, 12 (i.e., a2/b2) is in the interval 0.57-0.71,such as 0.62-0.66. In this manner, the required stiffness of the centresegment 5 a may be obtained.

In general, the article 1 may be arranged so that the ratio of the firstwidth a1 and the third width b1 is greater than the ratio of the secondwidth a2 and the fourth width b2, i.e.:(a1/b1)>(a2/b2).

Furthermore, the first, second, third and fourth widths a1, a2, b1, b2,respectively, may be configured so that:b1<b2*2 and a1<a2*2.

In addition to the arrangement of the first, second, third and fourthwidths a1, a2, b1, b2, as described above, the absorbent article 1 isarranged to provide the desired stiffness of the centre segment 5 a andthe entire absorbent article 1 by the above-mentioned arrangement of theabsorbent material in the absorbent core 5. This means that the centresegment 5 a may be configured for a stiffness in a wet condition whichis greater than that of each side segment 5 b, 5 c. This also means thatthe absorbent component, i.e., consisting of the centre segment 5 a andthe side segments 5 b, 5 c, may be configured with an ability to expandon wetting and to display a first volume in dry condition and a secondvolume in completely expanded wet condition, the second volume beinggreater than the first volume.

With reference again to FIG. 1, it can be noted that each channelsealing 9, 10 may have a length l1 which corresponds to the longitudinalextension of the crotch portion 8. Each one of the channel sealings 9,10 may have a length l1 which is between 5-50%, such as between 10-50%,such as between 28-38%, of the total length l of the absorbent article1. Furthermore, each channel sealing 9, 10 may have a length l1 which isbetween 10-60%, such as between 10-60%, such as between 20-60%, such asbetween 30-50%, of the length of the absorbent core 5.

A further parameter is the positioning of the channel sealings 9, 10along the absorbent article 1 in its longitudinal direction. Suchpositioning may be defined by choosing a suitable value for the distancel2 between the front edge 19 of the article 1 and the front edge 20 ofeach channel sealing 9, 10. Obviously, this means that decreasing saiddistance l2 means that the distance l3 between the back edge 21 of themain article 1 and the back edge 22 of the channel sealings 9, 10 willbe increased, and vice versa.

The position of the channel sealings 9, 10 along the longitudinaldirection of the absorbent article 1 may be chosen in a manner so thatthe distance l2 between the front edge 17 of the main article 1 and thefront edge 18 of each channel 9, 10 is between 15-40%, such as between22-25%, of the total length l of the article 1.

As mentioned above, the absorbent core 5 is enclosed by a core covercomprising an upper core cover side 11 and a lower core cover side 12.The absorbent core 5 may be manufactured as a single layer which iswrapped in nonwoven material and positioned between the topsheet 3 andthe backsheet 4 during manufacturing of the absorbent article 1.

Furthermore, the absorbent article 1 may comprise at least one additivematerial such as a skin care composition. In particular, it may be anadvantage if the topsheet 3 comprises at least one additive material inthe form of a skin care composition. The additive may be located on theparts of the topsheet covering the side segments 5 b, 5 c. This is dueto that the side segments 5 b, 5 c normally will be closest to the bodyof the wearer of the absorbent article 1.

According to what is known to the skilled person, the absorbent article1 may additionally be provided with further components such as fasteningtabs, elastic elements and other components which are commonly used inabsorbent articles such as for example baby diapers or incontinencegarments. Such additional components are not described in detail here.

With reference to FIG. 1, an absorbent core 5 is provided with a sealingarrangement 9, 10, 15, 16, i.e., comprising the above-mentioned channelsealings 9, 10 and the side seams 15, 16. As shown in FIG. 1, the sideseams 15, 16 extend along the side edges 17, 18 of the core.

The side seams 15,16 may define a first side seam width w3 and a secondside seam width w4, respectively, along the crotch portion 8 of theabsorbent article 1.

As shown in FIG. 1, the channel sealings 9, 10 may be generally straightand also generally parallel to the longitudinal axis x1. Also, the sideseams 15, 16 may be generally straight and generally parallel to thelongitudinal axis x1.

With reference to FIG. 3, the sealing arrangement 9, 10, 15, 16 may beconstituted by a welding pattern 23 produced by means of ultrasonicwelding. The welding pattern 23 may comprise welding spots 24 which arearranged in the form of a first row 23 a in which the welding spots 24are arranged along a first axis 25. Also, a further number of weldingspots 24 may be arranged in the form of a second row 23 b in which thewelding spots 24 extend along a second axis 26. Furthermore, the firstaxis 25 and the second axis 26 may extend in a manner so that theydefine a first angle α1 in relation to each other. In this manner, itcan be ensured that the absorbent core 5 can be manufactured with a highlevel of sealing strength in both its longitudinal and transversaldirection. The sealing strength provided by means of a welding processfor producing the channel sealings 9, 10 can be optimized by using theabove-mentioned configuration of the welding pattern 23.

The welding spots 24 may be of generally rectangular, circular, oval oroblong shape. Also, the above-mentioned first angle α1 may be in theinterval of 45-130°, 45-100° or 45-70°. As shown in FIG. 3, the firstangle α1 may be in the magnitude of 90°.

Also, as shown in FIG. 3, the first axis 25 may define an angle α2 withreference to said longitudinal axis y1 which may be within the interval30-60°.

FIG. 3 teaches one row 23 c of welding spots in each side seam 15, 16along the crotch portion 8, and three rows 23 c, 23 d, 23 e of weldingspots in each side seam 15, 16 along the front portion 6 and the backportion 7, respectively. Also, each side seam 15, 16 may define a fifthside seam width w5 and a sixth side seam width w6 along the frontportion 6 and back portion 7, respectively. By using an ultrasonicwelding pattern 23 as mentioned above, there is provided an absorbentarticle 1 with high sealing strength in both its longitudinal andtransversal direction. In this manner, high demands during wear andhandling of such an absorbent article 1 may be fulfilled, and thesealing strength will be sufficient also in wet condition.

As shown in FIGS. 3 and 4, the width w2 of the first row 23 a and thesecond row 23 b may be defined as an “effective” width in the sense thatit is equal to the sum of an effective width w2a of a welding spot 24 inthe first row 23 a and an effective width w2b of a welding spot 24 inthe second row 23 b. Each “effective width” can be defined as the lengthof a welding spot 24 in a transverse direction of the article 1, asindicated in FIG. 4. Similarly, the effective width w4c and w6c,respectively, of the third row 23 c of welding spots 24 is also shown inFIG. 4. The effective width of the third row 23 c in the crotch portion8 is the length w4c of a welding spot 24 in said transverse direction,as indicated in FIG. 4. Also, the effective width of the side seams 16outside the crotch portion 8 (as also indicated in FIG. 1) i.e., thecombined effective width of the three rows 23 c, 23 d, 23 e forming theside seam 16 is the sum of the lengths w6d, w6c, w6e in said transversedirection, as shown in FIG. 4.

The sum of the effective channel sealing widths w1, w2 and the first andsecond side seam widths w3, w4, w5, w6 in a transversal direction of thearticle 1 may be generally constant along the longitudinal length of thecore 5. This is particularly advantageous in a manufacturing processinvolving ultrasonic welding of the channels sealings 9, 10 and the sideseams 15, 16, since the manufacturing process can be arranged so that agenerally constant energy transfer is required as the ultrasonic weldingof the channels sealings 9, 10 and side seams 15, 16 is produced alongthe longitudinal direction of the core 5.

A method for manufacturing an absorbent article 1 will now be described.Firstly, the absorbent core 5 is formed by an absorbent component 5 a, 5b, 5 c, which absorbent component 5 a, 5 b, 5 c is enclosed by a corecover comprising an upper side 11 and a lower side 12. Next, the channelsealings 9, 10 are formed in a manner so that they join the upper corecover side 11 and the lower core cover side 12. In this manner, a firsteffective channel sealing width w1 and a second effective channelsealing width w2 are defined.

Consequently, the absorbent core 5 is formed with an absorbent component5 a, 5 b, 5 c enclosed by an upper core cover side 11 and a lower corecover side 12 and the two channel sealings 9, 10. The upper core coverside 11 and the lower core cover side 12 are joined to define saidchannel sealings 9, 10.

The article 1 (see FIG. 1) is formed by sandwiching the absorbent core 5between the liquid-permeable topsheet 3 and the liquid-impermeablebacksheet 4. The article 1 defines the longitudinal axis y1 and thetransversal axis x1 as described above. Also, the article 1 defines afront portion 6, a back portion 7 and a crotch portion 8. Furthermore,the channel sealings 9, 10 are positioned in the crotch portion 8, i.e.,the length l1 of each channel sealing 9, 10 may correspond to theextension of the crotch portion 8.

Furthermore, the sealing arrangement 9, 10, 15, 16 is formed with twoside seams which extend along the two side edges 25, 26 of the core 5.The side seams 15,16 define a third and fourth effective width w3, w4,respectively, along the crotch portion 8 and define a fifth and sixtheffective width w5, w6, respectively, along the front portion 6 and backportion 7.

In this regard, it should be noted that the effective widths w1, w2, w3,w4, w5, w6 are defined as the extension of said sealing arrangement 9,10, 15, 16 in the transverse direction of the article 1, along anycross-section of the crotch portion 8, front portion 6 and back portion7. Also, the sealing arrangement 9, 10, 15, 16 is formed in a manner sothat the sum of said first to sixth effective widths w1, w2, w3, w4, w5,w6 in the transversal direction is generally constant along said core 5.In this manner, the welding power for producing the sealing arrangement9, 10, 15, 16 may be generally constant along the absorbent core 5.

The channel sealings 9, 10 may be formed by an ultrasonic weldingpattern 23 which comprises a plurality of welding spots 24 which arearranged in the form of a first row 23 a in which the welding spots 24extend along a first axis 25 and also a second row 23 b in which thewelding spots 24 extend along a second axis 26. Also, the first axis 25and second axis 26 may be formed so that they define the first angle α1in relation to each other.

The absorbent component 5 may be formed so that the total amount ofabsorbent material of the centre segment 5 a is generally equal to, orgreater than, the total amount of absorbent material in each one of theside segments 5 b, 5 c. Furthermore, the manufacture method may beconfigured so that the ratio of the first width a1 and the third widthb1 is greater than the ratio of the second width a2 and the fourth widthb2. This corresponds to the description above with reference to FIGS. 1and 2.

The absorbent core 5 and the sealing arrangement 9, 10, 14, 15 may beformed in a manner so that the centre segment 5 a is formed between thechannel sealings 9, 10 and the two side segments 5 b, 5 c are formedoutside each channel sealing 9, 10. More precisely, the centre segment 5a has a first width a1 and each side segment 5 b, 5 c has a second widtha2. Also, the core 5 is formed with a third width b1 between the channelsealings 9, 10 and a fourth width b2 between a channel sealing 9, 10 anda side seam 15, 16.

The disclosure may be varied within the scope of the appended claims.For example, the materials and dimensions used for the different layersforming the absorbent article 1 may be varied, as indicated above. Theabsorbent article may further include leg elastics, standing gathers,crotch and waist elastics, side panels, fastening systems etc. as knownto the skilled man in the art and depending of the type of absorbentarticle intended.

The invention claimed is:
 1. An absorbent article comprising aliquid-permeable topsheet, a liquid-impermeable backsheet and anabsorbent core sandwiched between said topsheet and said backsheet,article being arranged along a longitudinal axis and a transversal axisextending in a perpendicular direction in relation to the longitudinalaxis and said article comprising a front portion, a back portion and acrotch portion, wherein said absorbent core is formed with a sealingarrangement comprising two channel sealings extending along saidlongitudinal axis in said crotch portion and defining a first effectivechannel sealing width and a second effective channel sealing width,respectively; wherein the sealing arrangement furthermore comprises twoside seams extending along two side edges of said core, said side seamsdefining a third and fourth effective width, respectively, along saidcrotch portion and defining a fifth and sixth effective width,respectively, along said front portion and back portion, wherein saidside seams have narrower effective widths in the crotch portion than inthe front portion and the back portion; said effective widths beingdefined as the extension of said sealing arrangement in the transversedirection of the article, along any cross-section of the crotch portion,wherein the sum of said first to sixth effective widths in thetransversal direction is generally constant along said core such that asum of the effective widths in the crotch portion are generally equal tothe sum of the effective widths in the front portion and back portion,wherein the first to fourth effective widths are different from thefifth and sixth effective widths.
 2. The absorbent article according toclaim 1, wherein the sealing arrangement is constituted by a weldingpattern produced by means of thermo and/or mechanical sealing.
 3. Theabsorbent article according to claim 1, wherein the sealing arrangementis constituted by a welding pattern produced by means of thermo-sealingor ultrasonic welding.
 4. The absorbent article according to claim 1,wherein the sealing arrangement is constituted by a welding pattern,wherein the welding pattern comprising a plurality of welding spotsbeing arranged in the form of a first row along the longitudinal axis inwhich each welding spot extends along a first axis, and a second rowalong the longitudinal axis in which each welding spot extends along asecond axis, said first axis and second axis defining a first angle inrelation to each other.
 5. The absorbent article according to claim 4,wherein said first angle is 45-130°.
 6. The absorbent article accordingto claim 4, wherein said welding spots are generally rectangular, ovalor oblong.
 7. The absorbent article according to claim 4, wherein saidfirst axis defines a second angle with reference to said longitudinalaxis which is within the interval 30-60°.
 8. The absorbent articleaccording to claim 1, wherein the absorbent core is formed with a centresegment having a first width (a1) as defined in the absorbent componentbetween the channel sealings and also two side segments, each having asecond width (a2) as defined in the absorbent component outside eachchannel sealing.
 9. The absorbent article according to claim 8, whereinthe absorbent component is formed so that the total amount of absorbentmaterial in the centre segment is generally equal to, or greater than,the total amount of absorbent material in each one of the side segments,wherein a third width (b1) is defined between the channel sealings and afourth width (b2) is defined between a channel sealing and a side seam,and wherein the ratio of the first width (a1) and the third width (b1)is greater than the ratio of the second width (a2) and the fourth width(b2).
 10. The absorbent article according to claim 9, wherein the ratioof the first width and the third width is in the interval 0.75-0.91, andthe ratio of the second width and the fourth width is in the interval0.57-0.71.
 11. The absorbent article according to claim 9, wherein saidfirst, second, third and fourth widths are configured so that b1<b2*2and a1<a2*2.
 12. The absorbent article according to claim 8, whereinsaid centre segment is configured for a stiffness in a wet conditionwhich is greater than that of each side segment.
 13. The absorbentarticle according to claim 8, wherein said side segments comprise atleast one additive material in the form of a skin care composition. 14.The absorbent article according to claim 1, wherein each one of saidchannel sealings has a length which is between 5-50% of the total lengthof said article.
 15. The absorbent article according to claim 1, whereineach channel sealing has a length which is between 10-60% of the lengthof the absorbent core.
 16. The absorbent article according to claim 1,wherein the position of the channel sealings along the longitudinaldirection of the article is arranged so that the distance between thefront edge of the article and the front edge of each channel is between15-40% of the total length of the article.
 17. The absorbent articleaccording to claim 1, wherein said absorbent component is constituted byone single core layer being enclosed by the core cover.
 18. Theabsorbent article according to claim 1, wherein said absorbent componentis configured with an ability to expand on wetting and displaying afirst volume in dry condition and a second volume in completely expandedwet condition, the second volume being greater than the first volume.19. The absorbent article according to claim 1, wherein said absorbentcore is generally rectangular.
 20. The absorbent article according toclaim 1, wherein said channel sealings are generally straight.
 21. Theabsorbent article according to claim 1, wherein said channel sealingsare generally parallel to said longitudinal axis.
 22. The absorbentarticle according to claim 1, wherein said channel sealings arepositioned within two corresponding channels which constitute sectionsof the absorbent core which are generally free from absorbent material.23. The absorbent article according to claim 1, wherein the side seamshave a longitudinal extension, wherein the channel sealings have alongitudinal extension, wherein the longitudinal extension of the sideseams is longer than the longitudinal extension of the channel sealings.24. An absorbent core for an absorbent article, said absorbent corecomprising a sealing arrangement with two channel sealings extendingalong said longitudinal axis in said crotch portion and defining a firsteffective channel sealing width and a second effective channel sealingwidth, respectively; wherein the sealing arrangement furthermorecomprises two side seams extending along two side edges of said core,said side seams defining a third and fourth effective width,respectively, along said crotch portion and defining a fifth and sixtheffective width, respectively, along said front portion and backportion, wherein said side seams have narrower effective widths in thecrotch portion than in the front portion and the back portion; saideffective widths being defined as the extension of said sealingarrangement in the transverse direction of the article, along anycross-section of the crotch portion, wherein the sum of said first tosixth effective widths in the transversal direction is generallyconstant along said core such that a sum of the effective widths in thecrotch portion are generally equal to the sum of the effective widths inthe front portion and back portion, wherein the first to fourtheffective widths are different from the fifth and sixth effectivewidths.